Continuous casting of steel using gas injection and special nozzle - to induce vortex in nozzle giving agitation and improved peripheral cooling

摘要

Method of casting steel uses a nozzle with inclined ribs, pref. of helicoidal section, over a limited length of the inner surface of the nozzle and at least in the region of the inlet for the steel. Inert gas is injected near the steel inlet to form a pocket of gas that provokes in association with the inclined ribs, the formation of a vortex at the heart of the steel entering the nozzle. In addition to forming this vortex the pocket of gas also extends the nozzle to improve the cooling conditions imposed on the liq. steel. Advantageously the ribs on the inner surface of the nozzle should be inclined in a sense to provoke the natural vortex produced by the injection of the inert gas. - The nozzle used in this method of casting is also claimed.